Compressor



Feb. 2, 1954 BRQWNE 2,668,004

COMPRESSOR Filed March 2, 1948 8 sheets-shet'l INVENTOR.

LINDSAY HBROk/NE BY ATrYs.

Feb. 2, 1954 L. H. BROWNE 4 2,668,004

COMPRESSOR Filed March 2, 1948 -8 Sheets-Sheet 2 mmvrm INDSAY H BEOWNE L. H. BROWNE Feb. 2,. 1954 COMPRESSOR 8 Sheets-Sheet 3 Filed March 2, 1948 INVENTOR. LINDSAY H Beam/E BY ATrYs.

Feb. 2, 1954 Filed March 2, 1948 8 Sheets-Shet 5 9a 91 4 Ill II II 47 a 114 VINVENTOR. LINDSAY 1-1. 520 w/vE 20M M W A T'TYS.

Feb. 2, 1954 BROWNE 2,668,004

COMPRESSOR z Filed March 2, 1948 '8 Sheets-Sheet 6 INVENTOR. LINDSAY H. BROWNE Patented Feb. 2, 1954 UNIT ED: FATE NT OFFICE COMPRESSOR Lindsay H.- Browne, Weston, Conm, assignor to. American Brake Shoe Company, Wilmington, Del;, a corporation .of Delaware Application Marchz, 1948, Serial No. 12,610

4 Claims. r V This invention relates to compressors and more. particularly to directly driven compressors of. the. type. whichare especially well adaptedto compressworking fluid, such-as air or the like, to relatively high pressures.

Compressors are. at the present time used for many purposes, such as, for example, in automobile service, stations for supplying compressed air for, inflating ,tires, and with paint spraying equipment. for supplying compressed air. to. the spray gun. Because of the variation in demand on compressors, used for the different purposes, compressors of different capacities are preferably provided" so: that the compressors may normally operate at" an optimum efficiency. Manufacturers. are.v therefore, faced with the practical.

necessity of providing. compressors of' various sizes and capacities, which multiplies the problem of supplying parts therefon. It is a primary object of my inventionto alleviate this .problem by enabling novel. direct-drive compressors of' various capacities .to'be, constructed wherei the parts thereof are. relatively widely interchangeable.

An-object ancillary, to the foregoing isto enable compressorsof various capacities to beconstructedhaving a relatively small. number. of. variable and total. parts.

Another object of 'my invention is to construct a novel; compressor which comprises a compact.

unit of'relatively'high. efficiency, and. which. may be. run in either, a vertical or horizontal position.

Another object of. my invention. is to. rovide a: reciprocating-piston type of compressor having two banks of cylinders, both of. which banks are embodied ina single housing.

A further object. of my. invention is to. enable thev construction. of a novel compressor of. the aforesaid reciprocating-piston type having. a plurality of high pressure and low pressure. cylinders embodied in the same housing.

An object ancillary tothe foregoing is to. con.-

struct a novel compressor of the, aforementioned.

ing those principles.

2'. of. suitable materials and wherein the drive shaft has substantially true, dynamic balance.

Another. object-is, to construct a novel compressor in such a manner that. strips of suitable material. such as steel'may be. utilized in. a, novel manner to, afford the bearing surfaces, for the yokes of the compressor and. to provide ready adjustment of. the fit of the. yokes relative to. the.

movable parts to which they are connected;

Yet another object. of'my invention is to construct" a novel compressor of the reciprocatingpiston type wherein, during operation thereof,.

the side thrust on the pistons is relatively small,

A further object is to afford a novelcompressor wherein the compression chamber is maintained in relatively free communicationwith the atmospherev in a novel andexpeditiousmanner:

until the compressor has reached a predetermined speed of operation, and. the oil pressure of the lubricating system thereof. has also reached a predetermined amount.

An object ancillary to the foregoing is to provide a compressor of the aforementioned; type.

with a novel unloader mechanism which is responsive in a novel and expeditious manner to.

both the speed ofoperation of the compressor and the pressure. of the oil in the. lubricating;

system.

Other and further objects of the present invention will be apparent fromthe following description and claims and are illustrated in the ac.-

companying drawings which, by way of illustra.

tion, show. preferred embodiments and-the principles thereof, and whatlnow consider to be thebest mode. in which I have contemplated apply-- Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes.

may be made as: desired by those skilledinthe art. without departing from the present'inventionandthe purview of the appended claims.

In the drawings:

Fig. 1- is an elevational view of a compressor embodying the principles of my invention, with certain parts broken away and with the casing therefor removed;

Fig. 2 is a sectional view takensubstantially on line 2-2 in Fig. 1, with thecasing shown in place;

Fig. 3' isa bottom plan View of: the. compressor shown in Fig. 1;

Fig. 4 is a detail view. of the valve mechanism.

ofthe compressor, taken substantially on. the line 44in Fig. 2;

Fig. is a detail sectional View taken substantially on the line 5-5 in Fig. 4;

Fig. 6 is a detail sectional view taken substantially on the line 65 in Fig. 4;

Fig. 7 is a sectional view taken substantially on the line 'I'I in Fig. 6;

Fig. 8 is a sectional view taken substantially along the line 8-8 in Fig. 2;

Fig. 9 is a detail view similar to Fig. 8 but showing the piston in a different position;

Fig. 10 is an exploded view of the yoke and associated mechanism shown in Fig. 8;

Fig. 11 is an enlarged detail View of a portion of the cam shaft shown in Fig. 2;

Fig. 12 is a detail sectional view of the unloader mechanism taken substantially along the line I2I2 in Fig. 14;

Fig. 13 is a detail view similar to Fig. 12 but showing the valve in a difierent operating position;

Fig. 14 is a detail top plan view of the lower body member of the unloader shown in Fig. 2;

.Fig. 15 is an enlarged detail view of the oil pump as shown in Fig. 1; and

Fig. 16 is an enlarged sectional view taken substantially along the line I6I6 in Fig. 1.

The compressor shown in the accompanying drawings, to illustrate the principle of my invention, comprises, in general, a compressing unit 33 connected to a motor 32 within a casing 34.

The motor 32 comprises a stator 36 and a rotor 31 mounted within a housing 39, and is mounted on the compressing unit with the lower edge portion of the housing 39, as viewed in Fig. 2, mounted in a rabbet 4| formed in the top end portion of the housing 43 of the compressing unit 30, and is held in position thereon by suitable means such as clamps 42 mounted on hold-down bolts 44 mounted in the housing #3.

The rotor 31 is keyed onto one end portion of a drive shaft 45 and is secured against longitudinal movement with respect thereto by two snap-rings 4] and 48 mounted in suitable snap-ring grooves formed in the drive shaft 45. It will be noted that in Fig. 2 of the drawings another snap-ring groove. 51! is shown which is not used with the rotor 31. This latter groove 50 is provided for use in other installations with motors of less horse-power rating than the motor shown in the drawings. In these other installations, the rotor of the smaller motor would be held on the drive shaft 45 by the snap-ring 51 and another snapring mounted in the groove 55. It will be apparent that, within the purview of my invention, snap rings can also be used at other positions on my drive shaft 45 to hold rotors of other sizes so that my drive shaft may be used with motors of various capacities.

The central portion of the drive shaft 45 is journaled in a ball-bearing 52 mounted in a sleeve 54 formed in the upper end portion of the housing 43 of the compressing unit 30. An inwardly extending flange 55 formed on the sleeve 54 restrains the bearing 52 from vertical upward movement, as viewed in Fig. 2.

The casing is substantially cylindrical in shape, having two end caps 51 and 58 which have openings therethrough covered with suitable material such as wire screens 68 and 6 I, respectively. A base member 63, having three projecting legs 65, 66 and 61', Figs. 1 and 3, is mounted within the casing 34 with the legs 65, 66 and 6'! projecting outwardly through the end cap 58 of the casing 34. The legs 55, 66 and 61 form supporting members for my compressor when the com- 4 pressor is disposed in the vertical position shown in Fig. 2.

The housing 43 of the compressing unit 39 is mounted in a rabbet '10 formed in the upper end portion of the base 63, as viewed in Fig. 2, and is secured thereto by suitable means such as mounting bolts 12.

The end portion of the drive shaft 45 opposite to that on which the rotor 37 is mounted, extends through, and is journaled in, a ball bearing I4 mounted in a sleeve 16 projecting inwardly from the base 63. The ball bearing I4 is restrained from outward, or downward movement, as viewed in Fig. 2, by a shoulder 18 formed in the sleeve I6. The lower end portion of the drive shaft 45, as viewed in Fig. 2, extends downwardly from the bearing I4 and projects into an oil pump Bll mounted on the lower end portion of the base 63 for a purpose which will be discussed in greater detail presently.

Between the bearings 52 and I6, two substantially oppositely disposed crank cams 84 and 8B, and two substantially oppositely disposed counter-weights 85 and 81, are formed on the drive shaft 45. Two cam blocks 88 and 39, made of a suitable material such as bronze, are mounted on,

the crank cams 84 and 86, respectively. Each of the cam blocks 88 and 89 are of two piece construction, the cam block 88 being split along a line 9|, Fig. 8, into two halves 93 and 94, Figs. 2, '7 and 8, and the cam block 89 being split in a similar manner into two halves 96 and 91, Fig. 2.

A yoke, I BI, Figs. 2, 8 and 9, comprising two separable end portions I03 and I 55, is mounted on the cam block 88, the two end portions I53 and 25 of the yoke being held together by bolts ID! and nuts 108. The yoke IBI may be made of any suitable material such as, for example, cast aluminum, and the end portions I53 and I I35 thereof include substantially rigid connecting rods, H5 and III, respectively, having low-pressure pistons I I3 and I I4 formed on the outer end portions thereof, the pistons H3 and H4 being slidably mounted in diametrically opposed cylinders H6 and Ill, respectively, in the housing 43 of the compressing unit 39. The drive shaft 45, by this connection between the crank cam 84 and the pistons I I 3 and I I4, is eifective, upon rotation, to reciprocate the pistons I I3 and H4 in the cylinders I I5 and Ill, respectively, as will be discussed in greater detail hereinafter.

Two Wear plates I23 and 124, made of a suitable material such as hardened and ground steel, are mounted on the inner faces I20 and HI of the end portions I03 and I05, respectively, of the yoke MI and project laterally therefrom into engagement with shoulders I26 and I2! disposed in recesses I29 and I38 formed in the outer edge portions of the two halves 93 and 94, respectively, of the cam block 88. The side member of the two end portions I53 and I05 of the yoke are under-cut to form lip I32 and I33 respectively, which are effective to normally retain the wear plates on the faces I2t and I2I, the configuration of the lips I32 and :33 being such that they are adapted to effectively retain wear plates of various thicknesses on the faces. I have found that relatively thin wear plates, such as, for example, wear plates having a thickness of sixthousandths of an inch, are well adapted for normal use in my novel compressor. However, the wear plates used in my yoke have sufficient resiliency that during assembly, when the yoke IBI is in disassembled condition, they may be readily snapped into, and out from under, the

ascends.

88;. maybe: ri-zadily-- installed during the assembly ofzmy novelzcompresson unit;

Thus it'; WilLbfi-f seen thatsthei wear; plates. I23: anriz l24z-providea good bearing surface between the cam. block 88 andtheyoke IIlI son th'at. itisunnecessary to: machine finish the inner faces fthe yoke: I01: to" the: extent. that would. otherwise: bezrequired. Furthermore; it will. be noted that: the wear: plates I23: and: I24- provide aneflicient and readily accomplishedv means for properly: fitting the; yoke IIlI on. the cam block 88- during", assembly of; my "novel compressor unit; or during an overhaul thereof, it merely beingnecesear-y to; mount wear plates having the proper thickness to give the; desired fit. on thefaces I and I21 during such. assembly.

A-.y.oke- I40, Fig.x2;s-imilar to the yoke-IIlI, andhaving two: separable; end portions I52: and IE3 held togetherby bolts: andznuts; similar to-bolts I61 andinuts I 08, is mountedontt-hecam block portions thereof, the-pistons IEI and; L62: beingreciprocably mounted. incylinders I64: and I85; respectively, in thehousingyflhof thecompressing unit Aswill: be more apparent hereinafter, the con.

struction of. my novel. compressing unit is such that. the drive shaftsfilfi may readily be-cast of anysuitable materiale such as iron and is easily balanced so as torhavesubstantially true dynamic balance;

As isloest: seen in Fig. 2, thelow-pressure-pistons. H3 and H4 have suitable compressionrings I6? and oil rings I63 mounted thereon, and the high-pressure pistons, likewise, have suitable compression. rings I wand; oil rings- I .12. mounted.

thereon.

Low-pressure cylinder heads I75 are mounted on the housing 43' of'tlie compressing unit; 30" in alignment with the low-pressure cylinders I I6" and. Ill, and. are secured thereto by bolts. I'll and I18 Likewise, vhigh-pressure cylinder heads I80. are mounted on the. housing. 43 in. alignment with the high-pressure cylinders I54 and I55 and are secured thereto by bolts I82 and'the bolts I18. The low-pressure: cylinder heads I15 each-have intake ports lfi l, Fig. 5-, which are in communication with the atmosphere through an intakemanifold I86, Fig. 1. Theinner end portion of the-intakeport I34, in each ofthe cylinder heads I75 is incommunication with a substantially semi-circular shaped chamber I38 which is in communication with an. annularpassageway lei! formed in the inner face of the cylinder head. I Intake valve I92, comprising substantially flat annular members made of suitable material such as. spring steel; arev yieldingly held against the inner face of each of. the: cylinder heads I15, in position. tocover the passageways l90,-.. by substantially annular-shaped valve springs. I96 mountedzon bosses IRE projecting inwardly from the cylinder heads. I15, the valvesprings being 6 held omthez bosses by: suitable; fasteningzmeans; such as. snap. rings; I98: andihaving v resilient: fingers 2.00; Figsler and;5;,engaged with. theinner surface of" the. valves I92? and. yieldingly holding;

the-valves I92in. engagement with the inner face:

of. the: cylinder heads. I15" in position. over the; annular passageways I911.- The valve springs: I94; are made offany suitableamaterial such as spring; steel, and are of. suchstrength that when. the low-pressure pistons H3 and H4 are stationarywithin thecylinders llfiiand III; or are, moving outwardly in a compression stroke,. they are; cf. fective. to; firmly. seat the valves. I92 against; the" inner face of the respective cylinder heads I15 to: thereby positively close the passageways l9.0f,.butwhenthe pistons I IS-and I I4. are moving inwards 1y they will. permit the; respective valves I92 to.- open-to thereby permit; air to be. drawn from. the. atmospherethrough the intake manifold. I 8.6,. the: intake port I 84; .theychamber I 88zandthepassagee way I Shinto; the cylinders IIS and Ill;

Substantially cylindrically shaped passageways- 204. extend from the; inner; faces of thecylinder heads I15 axially through the bosses I96: into: communication with enlarged passageways--; 20.6? which are in communication with exhaust ports: 20B;- extending laterally through the. respective cylinder heads H5. A valve 2I0, comprising a: substantially circular: shaped: plate made of' a. suitable material suchasspring steel, is mounted: in eachof the enlarged passageways 20B and. is. heldin engagement. with a shoulder or; valve. seat. 2I2. therein by a compression spring 214- mounted on aplug ZIB. screwed into the; respective cylinder head I15: The valve: springs; 2M are of. such strength; that, when the low-pressure pistons H3 and: IIII are. moving inwardly in. an: intake stroke, they are" effective to; firmly, seat the valves. 2 I Ii against. theshoulders 2 I2. to. there by close: theipassagewayslflfi in a. positive man-- ner; but. when the pistons H3" and. I I4 arezmow ing outwardly through the low-pressure cylinders'. H6; and Ill in a. compression stroke theywill permit the respective valves2I D'to open and thereby permit air'to be. forced by the pistons I I3" and H4: outwardly from the cylinders H6 and II -T through the. passageways 2M and 20.6 and: exhaust ports 268;.

The'exhaust port; 298 of each of. thelow-pressure: cylinder heads I75. is. connected by a separateintercooler 221! to an intake port 222;. Figs. 1, 6 811C117, of a respectivaadjacently dis? posed, high-pressure cylinder head I80, theainterconnection of the intercoolers 220 with the lowpressurecylinder heads I15 and. the highepressure cylinder; heads; I86 beingpieffected by suitable coupling means such; as. plates 22.4: and 2.25;. Fig; l, mounted on opposite ends of. the. intercoolers and attached to the: cylinder heads I15 and ISO; respectively, by'bo'lts 22:1 and 22 8. The intercoo'lers: 220 are shown. in the accompanying drawings as having smooth outer surfaces, but it will be. understood by: those skilledintheart that, if. desired; the intercooler may have cooling. fins formed thereon.

Thain-take port 222. in each'of the high-pres:- sure cylinder heads I80. is in communication with a' substantially semi circularly shaped chamber 236,.Figs. 6: and 7-, which opens into an.

annular shaped passageway" 232 formed in the:

inner face-of the'cylinder head I;

Intake. valves; 234,.Figs; 4: and 6, similar to. the valves I525; are yieldingly held againstthe inner; facesaof; each of the-cylinder heads I;8.Il,.in position; to cover; and: close; the passageway 232;. by

substantially annular-shaped valve springs 236 mounted on bosses 238 projecting from the cylinder heads i88, the springs 238 being held on the bosses by suitable fastening means such as snap rings 248 and having resilient fingers 2 52 engaged with the inner surface of the valves 234 for yieldingly holding the valves 234 in engagement with the inner face of the cylinder heads I88 in position over the annular passageway 232.

The valve springs 238 are made of any suitable material such as spring steel, and are of such strength that, when the high-pressure pistons l8! and I82 are moving outwardly in a compression stroke, the springs are effective to firmly seat the valves 234 against the inner face of the respective cylinder heads 88 to thereby positively close the passageways 232, but when the pistons NH and H32 are moving inwardly they will permit the respective valves 234 to open to thereby permit air from the corresponding low pressure cylinder to flow from the connected intercooler 228 into the intake port 222, and through the chamber 238 and the passageway 232 into the respective one of the high pressure cylinders I64 and I85.

Substantially cylindrically shaped passageways 244, similar to the passageways 294 in the low pressure cylinder heads, extend from the inner faces of the cylinder heads I88 axially through the bosses 238 into communication with enlarged passageways 248 found in the cylinder heads [88. The enlarged passageways 2 38 are in communication with exhaust ports 248 extending transversely through the cylinder heads 489. A valve 258, similar to the valve 2H3, is mounted in each of the enlarged passageways 24B and is held in engagement with a shoulder or valve seat 252 therein by a compression spring 254 mounted on a plug 258 screwed into the respective cylinder head [88. The valve springs are of such strength that they are efiective to firmly seat the valves 258 against the shoulders 252 during inward strokes of the pistons It! and 192, but permit the valves 259 to be unseated from the shoulders 252 during a compression, or outward, stroke of the pistons 15! and 82, to thereby permit air to be forced by the pistons i l and IE2 from the cylinders 64 and I65 outwardly through the passageways 244 and 248 into the exhaust ports 248 from which it flows into an aftercooler 288, Fig. 1, connected thereto.

The aitercooler 288 has an outlet connection 282, Fig. l, by which it may be connected to a storage tank, or the like, not shown, and also has an outlet connection 264, Fig. 2, by which it may be connected through a pipe 236 to an unlcader valve 218, in a manner and for a purpose to be discussed presently, so that compressed air flowing into the aftercooler 238 from the highpressure cylinder I84 and H85 may flow to the storage tank and to the unloader 218.

The oil pump 88, Figs. 1, 2, 15 and 16, disposed at the lower end portion of the base '63, as viewed in Fig. 2, is of the type commonly known as a gear-type oil pump, and includes a gear 214, Fig. 2, keyed to the cam shaft and in mesh with an idler gear 219 journaled on a bearing 218 carried by the base member 63. Both the gears 214 and 215 are mounted in a pocket 288 formed in the base member 63. A plate 282, having a recess 284 formed therein, is mounted on the base 63 and retains the gears 214 and 216 in the pocket 288. A passageway 288 extends upwardly from the recess 284 in the plate 282,

as viewed in Fig. 2, into communication with the pocket 288 between the two gears 214 and 218 on the pressure side of the gears.

A cover plate 288, having a passageway 298 formed therein, is mounted on the outer face of the plate 282 with the upper end portion of the passageway 298, as viewed in Fig. 2, in communication with the recess 284 in the plate 282. The lower end portion of the passageway 298 connects with a discharge passage 292 connected at one end by a tube 294 to the unloader valve 218 in a manner, and for a purpose, which will be described in greater detail presently. The other end of the discharge passage 292 is connected to a pressure relief valve 296 embodied in the cover plate 288.

The relief valve 296 includes an enlairged chamber 298 in the cover plate 288, connecting at one end to the discharge passage 292 and connecting at the other end to a passage 388 extending through a portion of the cover plate 289 into communication with a passageway 382 which extends through the plate 282 and is in communication with the pocket 288 between the gears 214 and 218 on the inlet side of the gears. A shoulder 384 is formed at the interconnection of the enlarged passageway 288 and the discharge passage 292, and a ball valve member 388 is held in engagement therewith by a compression spring 388, one end of which is in engagement with the ball and. the other end of which abuts a plug 318 screwed into the cover plate 238. The strength of the spring is such that during normal operation of the pump 88 the ball valve 386 is maintained seated against the shoulder 384 to thereby maintain the connection between the discharge passage 292 and the enlarged passageway 298 closed, but when the pressure of the lubricant pumped by the oil pump 88 exceeds a predetermined pressure, as determined by adjustment of the plug 318, the ball valve 385 is unseated from the shoulder 384 and lubricant is thereby permitted to circulate from the pressure side of the gears 214 and 21B through the passageways 286, 298, 298, 388 and 382 back to the pocket 288 on the inlet side of the gears 214 and 215.

The plate 282 and the cover plate 288, which comprise the lower end portion of the oil pump 88, as viewed in Fig. 1, are fastened to the lower portion of the base 63 by suitable means such as bolts 3E3 and 3M.

In addition to the legs 85, 58 and 81 for supporting my novel compressor in the vertical position in which it is shown in Figs. 1 and three other legs 328, 321 and 322, Figs. 1 and 3, are provided whereby the compressor may also be supported for operation in a horizontal position, that is, in a position wherein the entire compressor is rotated 90 in a counterclockwise direction from that shown in Fig. 1. The leg 328 forms a transverse projection from the leg 65, and the other two legs 32! and 322 project outwardly from a mounting plate 324 secured to the housing 43 of the compressing unit 38 by any suitable means such as welding.

The lower end portion of the housing base 63 forms the oil reservoir for the pump 89, and the base 63 is so constructed that, when the proper amount of oil is contained in the reservoir, the top of the oil is below the level of the cylinders H8, H1, IE8 and 55 and below the path of travel of the yokes l8! and I48 when the compressor is in either the vertical or the horizontal position and a tube 33I extends therethrou gh. l he end "portions o'f the tube 331 fit snugly'in the openings 328 and 32t,-and one end portien hei's a fia'ng-e 3'33 thereon in which an annular sealing-ring 335 is :mounted. The other end of "the tube 333 i 'ha's an "open-ing 3 31 tapped therein, in which is screwed a 'p'lug 339, also having an annular sealingering 3 H mounted therein. 'The seal-ing rings 335 and 134i :may be made of any suitable material -such as a. chlorabutadiene polymer n'eoprene "-readilyvisible through-the transparentsi-de walls of thecup 363.

A fan 370, comprising a hub BIZ 'and two blades 371 2-1111 $15, is'slidably-moulited'on the'up'per end portion 0i the "drive shaft 4 as viewed iii-Figs. 2 5nd 1 2, and is 'con'necteti thereto by La pin-andslo't connection for rotation therewith, a pin e71 'on the shaft iiiextending through a slot tit-in ithfe hu'b fit'll Upward movemen-tlef th-e'fan 370 relative :to "the 'drive ehaft tt is li-mited bye stop ring 381 mounted in "a 'groo've 382 in the 'sha'ft 35, and downward movement of the lan -34B :is

i-imited bythepin sil.

lever t'tt, having a 'shor-tarm '386 and. a long arm 3-Bl,--'e: tends through slot's 389 "and 3.98 in the hub 372 and the shaft 85, respectively, and 'is pivotally connected to the sha'ft flfi, fo'r rota'tion therewith, by a pin tea. i'rhe short armnaeor tne lever 3815 extends into n passagewayfifl 'Theend portionoi the tu-be e 3| ,=iembodying the I n'ange 333, ha s an o-pening 343 extending longitud-in'ally .therethrough which interco'nriects at i'ts =innerendportion with :an: opening :34 5 extending transversely through the tube. fifhe other :end portion of the tube 433! "has re longitudinally :extending opening 341 formed therein which ter- -minates iin spaced-relation to the transversely iextending opening 345. Azplurality of openings 339 -."exten'd transversely through the .sidewalls of the tube 331 surrounding the openin'g are and forin aeommunica'ting passageways between the aopeningdti and the interibriof thelbase fir3.

Two ilaterally projecting acollars and 5352, definings'a gTDOVe BSA, ar'eiformedon the tube 33! intermediate the endiportions thereon. The colllarsv35l -and:352 :are snugly fitted unto :an opening formed through a flange :35'5 twhichprdjetzts lupwardly as viewedzin Fig. 11,?"from the bottomof the :ibase 163. A spassageway 358, in communica- .tion with the groove 354, extends through athe fiange E58 and opens into the :pocket 28'11 'onithe inlet side of .the :gears 2711 and 276 :of the rail pump 80.

Screw threads are tapped into the outer end v.portion 'of the-opening 734 3 in the tube and into. An oil cup' SES, Fig. 3,.madeofanyisuitable transparent material such as, for example, :a methyl methacrylate iresin (."Lucite-), :is :rotatably mounted on the other end portion of the tube-.361 'Duringitheoperation of :mynovel com- 63 oilmay pass, asrequired, through the openings 349, the openings 34'], the groove 354 and the opening :358 into theinlet -side-of the oil pump 80, suitable filters, such as screensi365 and 366 being mounted on the tube 33:! on opjposite 'sides of thecollars 35 i and :352 to filter theoilentering the openings-MQ from the oil reservoir inithe base E3. It willrbe'apparent that, the'cup 363 being =.directly connected to the base '63 by the tube- 36 1,

the oil level within icup 363 will be the same the flange =4 30 and fifdrmed in the upper end portion-of the drive shaft and engages the lower end :portion of a waive irodltts of thetmiloaderli 7-H.

The :unloader 276 comprises an upper body member -398 and a lower body member flOiL-lfligs. :12 and 13, rconncteditogether bysuitableimeans such :as tb'ol'ts 402. The :body membersesa and 413!! rhave recesses M04 sand 4W5, respectively;

formed therein. The :Lr ecesses ltd-Sand 40.5 tare adjacent Ito teach other 'butare separatedby a. flexible diaphragm 1D! mounted between the uppenandflower bodylmenibers.

The .lower body "member 400 'of the iunloader 25!!! includes an outwardly projecting shaft 409 which is .journaled inball bearings 'd'll "and 412 mounted inthe. passageway 394 iinrthe :drive shaft it, the lower bearing *4 t2 seating on a -shoulder =41 4 formed sin thezpassa'geway 394 to .iimi't-movement of the unloader in a downward diretionpas vviewed:inli ig. T4, and a snap ring 41 6 mounted in a suitable groovezin :the :drive shaft 45 above :the hearing Mai :Iimitin'g movement of the 'unloa'der 210 inan upward direction.

The Waive :rod 896 extends through theshaft 459 unto the recess 405, wherein it terminates in a valve head 418 which has an annular shaped flange'il'i 9 projecting :from the lower face thereof. A valveadisc it? |,:f'ormed of suitabl'e material such as :a chlbra'buta'diene polymer, is mounted in ithe iiange i i9. Thevalveheadifl 8 hasi'ashoulder 422 formed ainthe outer peripheral :edge portion thereof which vis zadapted to s'ea't on San Linwardiy :pr'ojecting .ziiangei 424 :formed :on a valve 426 mounted within the recess 405 concentrically t the-valve head HB. Theflower end portion of the'ringi426, as'view'ed in Fig. 13, proj'ects downiw'ardly below theifi'an'ge 424 .to form a base 428,

and thenpper end portion or the ring 4216 ter- 'minates an outwardly projecting fiange M31). .iAthrust plate 432 is seated upon'the flange 430 :below the diaphragmdflidore purpose which 'will be discussed in greater detail hereinafter, and

a compression spring 4-34 is :Ipositi-oned between the =base of the recess 105.

to .yieldingly urge the ring 426 and the thrust plate 432 toward the diaphragm.

' A passagewayflii, Figs. 12 (and 1'4,"is formed in the ilow'er body member 400 :0f the 'unlo'ader did-and extends from the recess 405 ioutwardly through the side wall :of the lower body memher 40.0. :A valve nipple 438 ismounte'd in 'the inner end portion of the apassageway 436 and projects into the recess #05. eA'coupling member "440 attached to .on'e end portion 0f the tube 266 "which extends :from the aitercooler 261i is 15 t i], u vei :within :t ibase es, and will be '7 mounted in th-e out-er endlportion of'the passage- 1 1 way 436, and thus it will be seen that communication is established between the aftercooler 260 and the recess 405.

A substantially vertically extending passageway 442, as viewed in Fig. 12, is formed in the lower body member 400 of the unloader 210 and is in direct communication with a simiiar passageway 444 formed in the upper body member 398. The upper end portion of the passageway 444 is connected to the recess 404, above the diaphragm 407, by a passageway 446 formed in the upper body member 398, and the lower end portion of the passageway 442 is connected to the tube 294, extending from the oil pump 80, by a coupling 443 screwed into the lower body member 400.

Another passageway 450, Fig. 14, is formed in the lower body member 400, extending from the outer surface of the side wall thereof to the recess 405. A coupling 452, Figs. 1 and 14, is screwed into the outer end portion of the passageway 450 and is connected to one end portion of a tube 454, the other end portion of which is open to the atmosphere, Fig. 1. Thus it will be seen that, as

I will be discussed in greater detail presently, an

exhaust passage is provided by the passageway 450, the coupling 452 and the tube 454, from the recess 405 to the atmosphere.

A compression spring 456 is mounted in a recess 458 formed in the lower end portion of the shaft 409 on the bodyof the unloader 2'40, with one end portion engaged with the base of the recess 458 and the other end portion engaged with a washer 460 carried by and pinned to, the lower end portion of the valve rod 395. The spring 455 yieldingly urges the valve rod' 395 downwardly into engagement with the short arm 385 of the lever 384.

A pin 462, carried by the hub 312 of the fan 310, is in alignment with the free end portion of the long arm 381 of the lever 392 and the downward urging of the valve rod 396 by the spring 456 is efiective to yieldingly urge the lever 384 to rotate in a counter-clockwise direction, as viewed in Fig. 12, to thereby maintain the long arm 381 of the lever 384 in engagement with the pin 462.

Two tension springs GUI and 602, Fig. l, are connected between two bolts 604 on the hub 312 of the fan 310 and the pin 311, Fig. 2, and yieldingly urge the fan 310 toward the normal, lower, position shown in Figs. 2 and 12.

From the foregoing it will be noted that, as will be discussed in greater detail hereinafter, when my novel compressing unit is at rest in the vertical position shown in Figs. 1 and 2, the weight of the fan 310 together with the action of the springs GUI, and 602 holds the fan in the lower position shown in Figs. 2 and 12, to thereby hold the valve disk 42I oif from the valve nipple 430 and thereby maintain an open passageway from the aftercooler 260 through the tube 266, the passageway 435, the valve nipple 438, the chamber 405, the passageway 450 andthe tube 454 to the atmosphere, to thereby maintain the compressing unit in unloaded condition. However, as will be discussed in greater detail presently, when the compressing unit is being operated in a normal manner and at normal opcrating speeds, the air thrust on the fan 310 is sufficient to raise the fan against the stop ring 38I out of engagement with the lever 384, Fig. 13, and the pressure of the oil pumped by the oil pump 80 into the chamber 404 is efiective to move the diaphragm 401 downwardly from the position shown in Fig. 12 to that shown in Fig.

13 to thereby move the thrust plate M8 and the ring 426 downwardly against the urging of the spring 434 and thus move the shoulder 424 down out of engagement with the valve head MB. This movement of the fan 310 and the shoulder 424 of the ring 423 frees the valve 418 for downward movement, and, therefore, the spring 456 is effective to move the valve 4 I 8 downwardly and thereby move the disk 42! into engagement with the valve nipple 438 to thereby close the passageway 435 and load the compressing unit.

At any time during the operation of my novel compressing unit if the speed of rotation of the drive shaft 45, and, therefore, if the fan 3'50 falls below a predetermined speed, or, if the pressure of the oil discharged by the oil pump falls below a predetermined pressure, the spring 456 is rendered inefiective to maintain the valve disk 42! in closed position on the valve nipple 438 and the compressing unit is unloaded. Thus it will be seen that my novel unloader 2'10 comprises an effective means for maintaining my novel compressing unit unloaded during the starting thereof until the speed of operation and the oil pressure have raised to their normal amounts, and also comprises a safety unit for unloading the compressor during operation of my compressing unit if either the speed of operation or the oil pressure falls below a predetermined amount.

When my novel compressing unit is mounted in the previously discussed horizontal position for operation, the operation of the unloader 210 is substantially the same as when the compressing unit is in the vertical position just discussed, the principal difierence being that the springs 60! and 502, unassisted by the force of gravity on the fan 310 are relied on to hold the fan 310 in normal, lowered, position.

The housing 43 of the compressing unit 30, and the cylinder heads I15 and I80 have cooling fins 465 formed thereon and it will be apparent that the fan 3'), when my compressor is in operation, is effective to draw air in through the screen 50 in the cap 51 and force it down through the casing 34, over the motor 32, and the compressing unit 30, and out the screen GI in the cap 58, the air thus forced through the casing 34 passing over and between the cooling fins 455 and passing over the intercoolers 220 and the aftercooler 250, to thereby effect cooling of the compressing unit 30 and of the air passing through the intercoolers 220 and the aftercooler 260.

Lubrication of the cams 84 and 85, the cam blocks 86 and 89, and the yokes IM and I40 is effected by the oil pump 80 through the drive shaft 45. For this purpose a passageway 410 is formed in the drive shaft 45 which interconnects the recess 284 in the oil pump 80 with passageways 412 and 473 which extend transversely through the cams 34 and 86, respectively, and are in communication with recesses 415 and 416 formed in the cam blocks 88 and 89, respectively. Two passageways 478 and 419 extend transversely through the cam blocks 88 and 89, respectively, and interconnect the recess 415 with the recesses I29 and I30, and the recess 416 with the recesses I55 and l56. Thus, it will be seen that, during operation of my compressor, oil is pumped from the pump 80 through the passageway 4'10 and the respective transverse passageways extending therefrom into the spaces between the cam 84, the cam block 88 and the yoke NH, and into the spaces between the cam 86, the cam apes-ta "black '89 and the yoke -l40 tolubricate these-respective -pa-rts.

Operation of the compressors'hown Figs. .1-16

disk 42! is 'out of engagement with the valve nipple 43B, and an open passage .is, therefore,

'maintained from the Ehigh pressure cylinders I84 position' shown in FigsLL-Tand 2,'when, .upon initiation of .an operation of .my compressing unit, the m'otor32 .isienergized tothereby effect rotation of'the drive shaft -45,-the fan "310 is caused to :rotate, and the pump 2180 1S .ncausecl to operate. Operation of the :pump 0 forces oil from the reservo'ir:in the "base .63 "through the-drive shaft -45 'to'lubri'cate-thezcamblocks 88 and 84 and the yokes 1.01 and 1'40, -.as previously described, and forces oil through :the tube 294, the coupling :merriber 4-48 and the :passageways 44.2, 444 :and

446 into :the recess "4M above'the diaphragm 4G! in the unloader 270. As the speed of the com-- ,pressor increases, the :pressure 10f theoil being pumped by the pump ".80 increases and finally becomes effective to deflect the diaphragm 4M downwardly to thereby press the thrust plate 432 and the valve ring 426 downwardly against the urging of the .spring 434 to the position .shown'in Fig. 1.3 wherein thezbase 4-28 .of the ring 1' '426 rests on the base-of the recess 405. This downward movement-of the ring 426 .moves the flange 424 thereof out of engagement with the 'valve head 4 L8 and thereby :frees the valve head 41B and the valve rod .396 to the action of the spring 456. However, until thecornpressor has obtained its normal speed of operation, the weight of the fan 3') and the :action of the springs 60-1 and '6922 holds the lever 1384 against full counterclockwise rotation and, therefore, 4

restrains movement "of the valve head M8 and the valve rod 396. As the speed of the compressor increases the force .of the air on the blades 314and "3-15 of the revolving fan 310 lifts "the fan .310 on the shaft 45 to thereby permit counter-clockwiserotation of the lever 384, until, when the speed of the compressor has increased "to the normal operating speed thereof, the fan 319 :has been lifted to its fully raised position and the spring 456 has moved the valve head MB and the valve rod 396 downwardly to the position shown in Fig. 13, wherein the valve disk 42l is seated on the valve nipple-438 and closes cylinders-164 and H55 and the aftercooler 260 to the atmosphere and establish loaded condition of the compressor. Thus it will be seen that during starting-the compressing unit .30 .is maintained in unloaded condition by my novel unlcader 210 until both the oil pressure of the pump 88 and the-speed of rotation of the fan .31!) have reached tcertain predetermined amountsand .thatatany timeiduring the opera- .tion of my novel compressor if either the pressure of the oil pumped 'to the unloader 210 by Cir the nipple 438 to thereby close the high pressure 7 the pump 80 drops below a predetermined level,

or the speed'of rotation of the "compressing unit 30, and, therefore, of the fan 370, falls bl'ow a predetermined speed, the unloader 27d 'will -b'e caused to atomatically open tot-hereby open-the aftercooler 260 to the atmosphere and relieve the load-onthe-compressing unit 30.

Also, during rotation of the-drive'shaf-tfi, as

will be apparent to those skilled in the art, the rotation of the-cams-8'4 'and 86 within the "cam "blocks as and 89 is effective to reciprocate the 'yokes [GI and Mill and, therefore, the l dw pressure pistons H3 and H4 and the high-pressure pistons it! and 162, respectively. lnthisponnection it will be noted't'hat with'my'novelyoke arrangement the side thruston the'low-pressure and highpressure pistons is relatively small, the force exerted by the well lubricated cam blocks 88 and 89 .on the jyokes I ill and 140,7respectively, within which they are rela'tive'ly'free- 1y slidable, being substantially longitudinal of the respective ,yokes, and thus'the wear on the sides of the pistons and the cylinder walls is reduced to a minimum.

"During each complete rotation of the cam shaft 45 the low-pressurepistons 'HBand I14, and the high-pressure pistons [El and [62 are each caused to reciprocate through an "intake stroke and'a compression stroke; The arrangement of the pistonsand the cams is such that while half the pistons are "moving through compression strokes the others are moving through suction strokes so that the "feeding of compressed air from the compressing unit 30 is substantially continuous. Each pairof adjacent low-pressure and high pressure cylinders comprises substantially a complete pumping unit. For exaniplejit will be seen that when the low pressure piston H4 is moving through a compression stroke'the intake valve N74 for that piston 'is closed and the exhaust valve "2 [0 therefor is open so that Lair is forced from the cylinder head I15 on the cylinder Ill through the intercooler "Z10 connected thereto to the cylinder head I80 on the high pressure cylinder [65. Thehigh-pressure piston I62 is at that time moving through an intake stroke, so the exhaust valve 250 therefor is closed an'd'the inlet valve 234 is open and the air forced from the low-pressure cylinder ll'l enters the high pressure cylinder 165. During 'the'next one hundred and eighty degrees of rotation of the camshaft "45 the movement'of thepistons H4 and 1.62 is reversed so that "the low-pressurepiston l M is on an intake 'stroke,"with the exhaust valve 210 therefor closed and the intake valve 192 and .air is, therefore, forced under high pressure from the high-pressure cylinder 465 to theraftercooler .280 from whence itflows to a suitable storage tank or thelike. :During these strokes-of. the low-pressure piston :E 34 and the high-pressure piston 162, the low pressurepiston 11.3 and the high-pressure piston 4 6! respectively, on the other side of the housing 43 are moving in the opposite direction so that, as previously -stat-ed it will be apparent that the feeding of coml pressed air from the aftercooler 280 to the storage tank is substantially continuous.

From the foregoing it will be seen that I have provided a novel compressor embodying a novel yoke arrangement whereby the forces exerted on the high and low pressure pistons is substantially longitudinal of the path of reciprocation of the pistons and the side thrust on the pistons is at a minimum.

Also, it will be seen that I have provided a compressor of the aforementioned type wherein the yokes, connecting rods and pistons may be integrally cast of suitable material such as aluminum and wherein the yokes may be fitted to the drive mechanism therefor in a novel and expeditious manner.

In addition it will be seen that when either the pressure of the oil pumped by the oil pump is below a predetermined pressure, or the speed of rotation of the drive shaft of the compressor is tion, and which is relatively small in size and compact in form, and presents a pleasing appearance.

Also it will be noted that my novel compressor is constructed so as to provide good interchangeability of parts between the various capacities of compressors which may be manufactured and assembled.

Hence, while I have illustrated and described the preferred embodiments of my invention, it is to be understood that these are capable of variation and modification and I therefore do not wish to be limited to the precise details set forth, but desire to avail myself of such changes and alterations as fall within the purview of the following claims.

I claim:

1. A compressor comprising an elongated housing embodying diametrically opposed cylinders extending transversely to the longitudinal axis of said housing, said housing having a closed end, and lateral sides projecting transversely to said closed end, said housing having a vertical operative position wherein said one end is disposed downwardly, and a horizontal position wherein one of said sides is disposed downwardly, said one side being substantially parallel to the longitudinal axis of said cylinders, pistons reciprocably mounted in said cylinders, a drive shaft journaled in said housing and extending longitudinally of said housing between said opposed cylinders substantially transversely to said cylinders, means on said drive shaft for reciprocating formed in said one end portion of said housing axis of said housing, said housing having a closed end and side walls projecting from said end, said housing having a vertical operative position wherein said one end is disposed downwardly, and a horizontal position wherein one side is disposed downwardly, said one side being substantially parallel to the longitudinal axis of said cylinders, pistons reciprocably mounted in said cylinders, a drive shaft journaled in said housing and extending longitudinally of said housing between said opposed cylinders substantially transversely to said cylinders, means on said drive shaft for reciprocating said pistons simultaneously upon rotation of said drive shaft, an oil pump mounted on said housing and operatively connected to said drive shaft for feeding oil to said means for lubricating the latter upon rotation of said drive shaft, and means for feeding oil to said pump, said last named means including a reservoir defined by said one end portion of said housing, an elongated pocket formed in said one end portion of said housing at the junction of said closed end of said housing and said side wall on said one side, said pocket being disposed in substantially parallel relation to said longitudinal axis of said cylinders, an elongated tube mounted in and extending along said pocket, said tube having perforations in the side walls thereof for admitting oil thereinto from said reservoir, and conduit means operatively connected to the interior of said tube and the inlet of said oil pump for feeding oil from said tube to said pump.

3. In an air compressor of the type including supporting means, a housing mounted on said supporting means and embodying two pairs of diametrically opposed cylinders, and pistons reciprocably mounted in said cylinders, two yoke members, each of said yoke members interconnecting the pistons mounted in a corresponding one of said pairs of cylinders and having recesses formed in opposite end portions of each of two oppositely disposed inner edge portions thereof, plate members mounted in operative position on said edge portions, said plate members having ends projecting into said recesses for releasably holding said plates in said operative position on said edge portions, the said recesses in the yokes being bevelled to afford overhanging lips for accommodating plate members of varying thicknesses, two cams carried by said drive shaft for rotation therewith and projecting transversely therefrom in substantially opposite directions, each of said cams being disposed within a corresponding one of said yoke members, two block members, each of said block members being reciprocably mounte in a corresponding one of said yoke members between said yoke member and said corresponding cam and having outer edge portions engaged with said plate members mounted in said yoke member, said cams being operable upon rotation of said drive shaft to reciprocate said block members along said plate members within said yoke members transverse y to said cylinders and to reciprocate said yoke members and said pistons longitudinally of said cylinders, and means for rotating said drive shaft.

4. A compressor comprising an elongated housing adapted to set on a supporting surface and embodying diametrically opposed cylinders, pistons reciprocably mounted in said cylinders, a drive shaft extending between said opposed cylinders in substantial transverse relation thereto, cam means mounted on said drive shaft to reciproeate the pistons, there being an open connection between the cam means and the pistons, said housing having both a vertical operating position in which the drive shaft extends substantially vertically in relation to the plane of the supporting surface and a horizontal position in which the drive shaft extends substantially horizontally in relation to the plane of the supporting surface, the housing being adapted to be pivoted about a bottom edge from said vertical to said horizontal position, a, reservoir in said housing for holding a supply of oil at a level below said cylinders when said compressor is in either the vertical or horizontal operating position, the oil reservoir including a storage area at the bottom, the housing being located adjacent said edge and substantially below the level of the cylinders whereby the level of the oil in the storage area is below the level of the cylinders in either the vertical or horizontal position of the housing thereby assuring that the pistons do not pump oil in either of the two said positions, and means including a conduit and an oil pump operatively connected to said drive shaft and said area for feeding oil to the cam means.

LINDSAY H. BROWNE.

References Cited in the file of this patent Number Numb er UNITED STATES PATENTS Name Date Olin Jan. 5, 1909 Pocock et a1 Apr. 13, 1909 Alvergnat Oct. 25, 1910 Levey Dec. 6, 1910 Walker Apr. 16, 1918 Carver Dec. 25, 1923 Heller Apr. 12, 1938 Hirche May 3, 1938 Whitfield July 12, 1938 Getchell et al Nov. 1, 1938 Touborg Feb. '7, 1939 Fette Oct. 17, 1939 Consley June 1'7, 1941 Mantle June 2, 1942 Morrison June 6, 1944 Maniscalco July 9, 1946 Cornelius Oct. 5, 1948 FOREIGN PATENTS Country Date Great Britain 1936 

